Carbalkoxyalkyl diphenyl ethers



i United States Patent 2,995,587 CARBALKOXYALKYL DIPHENYL ETHERS Donovan R. Wilgus, Richmond, Calili, assignor, by mesne assignments, to the United States of America as. represented by the United States Atomic Energy Commission No Drawing. Filed May 29, 1958, Ser. No. 738,649 3 Claims. (Cl. 260-4109) This invention is directed to new compositions of matter; that is, the new compounds, carbalkoxyalkyl diphenyl cthers.

The new compounds of this invention can be used as base oils for lubricants in general, including use as hydraulic fluids and as base oils for grease compositions. When used as base oils for greases, for example, carbalkoxyalkyl diphenyl others can be heated with grease thickening agents to a temperature suflicient to form a uniform blend, followed by cooling. High shearing forces, such as obtained by the Manton-Gaulin homogenizer, can also be used to disperse the thickening agents in these new base oils.

In addition to the above, these new compounds are particularly useful as base oils wherever lubricants are exposed to radiation. The irradiation of organic liquids by means of neutrons, X-rays, or gamma rays increases the viscosity of organic liquids. This viscosity increase is believed to be due to polymerization and cross-linking. In the application of nuclear energy for the generation of electric power, there are numerous frictional surfaces which require lubrication. It is essential to use mechanical equipment containing gears, bearings, journals, etc., all of which require lubrication. Irradiation of the usual lubricants results in the formation of heavy, viscous, or solid materials which are ineffective as lubricants. Furthermore, oxidation of lubricants in general is greatly increased by irradiation.

It is an object of this invention to provide new compositions of matter which are useful as base oils for lubricating compositions.

In accordance with this invention, it has been discovered that the new compounds, carbalkoxyalkyl diphenyl ethers, are useful as base oils for lubricating cornpositions.

The new compounds described herein are liquid at normal temperatures and they are particularly useful as lubricating oils, such as hydraulic fluids; as base oils for lubricating compositions used in the lubrication of internal combustion engines; base oils for grease compositions; and lubricants in general. These new oils are particularly resistant to radiation.

The carbalkoxyalkyl diphenyl ethers of the present invention are represented by the following formula:

ice

wherein R is a divalent, straight-chain or branched chain, saturated hydrocarbon radical containing from 2 to 17 carbon atoms, and R is a straight-chain or branched chain, saturated hydrocarbon radical containing from 1 to 18 carbon atoms, and R is hydrogen or the radical R C -O-R1 wherein R and R are the same as described hereinabove.

Examples of the R radical include divalent radicals derived from propane, butane, isobutane, pentane, 2- methyl butane, 2,3-dimethyl propane, hexane, heptane, octane, decane, dodeeane, tetradecane, hexadecane, octadecane, etc.

Examples of the R radicals include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, anyl, octyl, decyl, do decyl, etc.

The compounds described herein can be prepared as follows:

Diphenyl ether and an acid catalyst (e.g., anhydrous aluminum chloride) are mixed in a vessel equipped with EXAMPLE I Preparation of carbethoxy decyl diphenyl ether and bis(carbethoxy decyl) diphenyl ether A mixture of 170 grams (1.0 mol) of diphenyl ether and 133 grams (1.0 mol) of anhydrous aluminum chloride was charged to a reaction vessel. To this mixture was slowly added (dropwise) 2.12 grams (1.0 mol) of ethyl undecylenate. The reaction temperature was maintained at 45 to 50 C., using ice water as an external coolant until all of the undecylenate had been added. The whole mixture was then heated at a temperature of -70 C. for a period of five hours, after which the mixture was diluted with 1 volume of benzene, then poured onto ice-diluted hydrochloric acid. When the mixture had been warmed, the benzene layer separated from the aqueous phase. This benzene layer was washed with water until neutral, then dried over anhydrous sodium sulfate, and filtered. The benzene was removed by distillation, after which carbethoxydecyl diphenyl ether and bis(carbethoxydecyl) diphenyl ether were recovered by distillation at reduced pressures.

Table I hereinbelow presents physical properties of the carbethoxydecyl diphenyl ether and bis(carbethoxydecyl) diphenyl ether of Example I hereinalbove.

3 4 A L H ii on oiiwni 5 n.) doom.

1 r a r C- CH C-O-G H Structure all? I a l g Compound Oarbethoxydecyl Diphonyl Ether Bis(earbethoxydecyl) Diphenyl Ether nnwnnon Fraction:

(:1) Boiling Range. F., at mm Hg 374-410 5544503 (b)v Description Heart Out Heart Out Phy(siea1 lggpfrties: .es.

a) HIP 25.7 'r 87.4 4.53 10.6 P Fllorl lgsfiosity a I 01125 458 611, i orawo cs. -13 +16 0! 13.0001: 34 8 (c) ASTM a 1 (100 F. to r F.) 0.768 0.686 Viscosity In 98 111 e Pour Point, 60 55 Viscosity at Pour Point, cs

' (extrapolated)- 170 000 1 ,000,000 (0) Refractive Index, n 1. 5187 1. 5038 material to be tested was. sealed in a stainless steel capsule in an atmosphere of helium. The fluids were irradiated at two dosage levels at 60 F., and the viscosity changes were noted.

The gamma radiation source used herein was the spent nuclear reactor fuel canal facility located at the Materials Testing Reactor, National Reactor Testing Station, Idaho.

TABLE II Carbe- Bis(carbe- Hydrothoxythoxy- Radiation stability carbon decyi decyl) 2 Oil 1 Diphenyl Diphenyl Ether Ether A. Viscosity Change at 100 F.,

Percent:

(a) Dosage era /s. Carbon- 1.13 +37. 7 +2. 63 +5. 6.31 +187. 0 +19. 2 +106. 0 B. Viscosity Change .at 210 F.,

Percent:

(11 Dosage 10 ergs/g. Carma ArOalilornia naphthenic base white oil having a viscosity of 70 m. at

'group consisting of l-carbethoxy-methyl::onyl diphenyl ether and bis(carbethoxy-rnethylnonyl) diphenyl ether.

2. l-carbethoxy-methylnonyl diphenyl ether; 3. Bis(carbethoxy-methylnonyl) diphenyl ether.

References Cited in the file of this patent UNITED STATES PATENTS Haslam Dec. 9, 1952 OTHER REFERENCES Van Loon: Chem. Abst., 44, 7058 (1950). Mincher: KAPL-73l, Apr. 2, 1952, pages 3, 4 and 7. 

1. A CARBALKOXYALKYL DIPHENYL ETHER SELECTED FROM THE GROUP CONSISTING OF 1-CARBETHOXY-METHYLNONYL DIPHENYL ETHER AND BIS(CARBETHOXY-METHYLNONYL) DIPHENYL ETHER. 